Pure Tone Audiometry (PTA) Test in Pakistan at Chughtai Lab

Pure Tone Audiometry (PTA) at Chughtai Lab

Pure Tone Audiometry (PTA) is the gold standard diagnostic intervention utilized to evaluate an individual’s hearing threshold levels. This non-invasive, behavioral hearing test measures the peripheral and central auditory systems’ capacity to perceive various sound frequencies. By determining the quietest sounds a subject can hear at different pitches, PTA assists audiologists and occupational health specialists in identifying the precise degree, type, and configuration of hearing loss. At Chughtai Lab, Pakistan’s premier diagnostic network, this specialized audiology service is offered with a particular focus on corporate health, pre-employment screenings, and routine occupational health surveillance. The test is conducted within highly calibrated, sound-treated environments using advanced diagnostic audiometers to ensure absolute clinical precision.

The auditory system is a complex pathway comprising the outer ear, middle ear, inner ear, and the vestibulocochlear nerve (cranial nerve VIII) which transmits signals to the temporal lobe of the brain. Pure Tone Audiometry systematically evaluates this entire pathway. It utilizes two primary modalities: air conduction and bone conduction. Air conduction testing assesses the entire auditory system (from the external auditory canal through the middle ear to the cochlea and auditory nerve) using calibrated headphones or insert earphones. Bone conduction testing bypasses the outer and middle ear by placing a bone vibrator directly on the mastoid process, stimulating the cochlea directly. Comparing these two modalities allows clinicians to pinpoint whether a hearing deficit originates from a mechanical obstruction in the outer or middle ear (conductive hearing loss) or from damage to the sensory hair cells of the cochlea or the auditory nerve (sensorineural hearing loss).

For corporate clients across Pakistan, maintaining workforce health is both a regulatory compliance requirement and a moral obligation. Industries such as manufacturing, aviation, textiles, construction, and heavy engineering expose employees to prolonged, high-decibel noise levels. This exposure can lead to Occupational Noise-Induced Hearing Loss (ONIHL), a progressive and irreversible sensory impairment. Chughtai Lab provides this specialized PTA service to help corporations establish baseline hearing profiles for new hires, monitor existing employees through annual surveillance programs, and comply with national and international occupational health and safety standards. By utilizing state-of-the-art diagnostic equipment and standardized protocols, Chughtai Lab delivers highly reliable audiological data crucial for corporate wellness programs and legal medical documentation.

Clinical Procedure: What to Expect

Patient Preparation

To ensure the utmost accuracy of the Pure Tone Audiometry test, specific patient preparation is essential. Because PTA relies on the patient’s subjective responses to faint sounds, any external interference or temporary physiological changes can skew the results. Patients scheduled for a PTA at Chughtai Lab should adhere to the following preparation guidelines:

• Avoid Loud Noise Exposure: Patients must avoid exposure to loud noises (such as concerts, heavy machinery, firearms, or loud music through headphones) for at least 16 hours prior to the test. This precaution prevents a physiological phenomenon known as Temporary Threshold Shift (TTS), which can temporarily worsen hearing thresholds and lead to an inaccurate diagnosis of permanent hearing loss.
• Otoscopic Examination: Before commencing the audiometric test, a trained clinician will perform an otoscopy to inspect the external auditory canal. The canal must be clear of impacted earwax (cerumen), foreign bodies, or active infections. Impacted cerumen can cause a temporary conductive hearing loss of up to 20 to 30 decibels, which would invalidate the PTA results. If significant wax is present, it must be professionally removed prior to testing.
• Manage Acute Illnesses: If the patient is suffering from an acute upper respiratory tract infection, severe nasal congestion, or an active middle ear infection (otitis media), it is advisable to reschedule the test. These conditions can cause Eustachian tube dysfunction, leading to negative middle ear pressure or fluid accumulation, which temporarily alters hearing thresholds.
• No Special Fasting Required: There are no dietary restrictions or fasting requirements for Pure Tone Audiometry. Patients can eat, drink, and take their routine medications as prescribed.
• Provide Medical History: Patients should bring any previous audiograms, details of occupational noise exposure, history of ear surgeries, and a list of current medications, especially known ototoxic drugs like aminoglycoside antibiotics, high-dose loop diuretics, or platinum-based chemotherapy agents.

During the Procedure

The Pure Tone Audiometry procedure is entirely painless, non-invasive, and typically takes between 20 to 30 minutes to complete. The test is conducted by a qualified audiologist or a trained audiology technician within a specialized, soundproof audiometric booth designed to eliminate ambient background noise. The step-by-step clinical process is detailed below:

• Patient Positioning and Instructions: The patient is seated comfortably inside the soundproof booth. The audiologist provides clear, detailed instructions. The patient is instructed to respond immediately whenever they hear a tone, no matter how faint or distant it may seem. Responses are usually indicated by pressing a hand-held response button, raising a hand, or verbally confirming.
• Air Conduction Testing: The audiologist places calibrated supra-aural headphones or disposable insert earphones over or into the patient’s ears. The test typically begins in the better-hearing ear if a difference is reported. The audiologist presents pure tones at specific frequencies, typically starting at 1000 Hz, which is highly relevant for human speech perception, and then testing 2000 Hz, 4000 Hz, 8000 Hz, 500 Hz, and 250 Hz. The intensity of the sound is adjusted using a standardized bracketing method (the Hughson-Westlake method), decreasing the volume in 10 decibel (dB) steps when the patient hears the sound, and increasing it in 5 dB steps when they do not, until the absolute threshold is determined.
• Bone Conduction Testing: If the air conduction results indicate any degree of hearing loss, a bone conduction test is performed. The headphones are removed, and a small bone conduction oscillator is placed on the mastoid bone behind the test ear, held in place by a metal headband. Tones are presented again, typically at frequencies from 250 Hz to 4000 Hz. This directly stimulates the inner ear, allowing the audiologist to calculate the “air-bone gap” and differentiate between conductive and sensorineural hearing deficits.
• Masking (If Required): In cases where there is a significant difference in hearing sensitivity between the two ears, sound presented to the poorer ear may cross over through the skull bones and be heard by the better ear. To prevent this “cross-hearing,” the audiologist will introduce a continuous, gentle rushing noise (masking noise) into the non-test ear, ensuring that only the test ear is evaluating the pure tones.
• Safety and Comfort: The procedure is completely safe with zero risk of radiation or physical discomfort. The audiologist monitors the patient throughout the test through a window in the soundproof booth to ensure compliance and comfort.

When is a Pure Tone Audiometry (PTA) Performed?

Occupational Noise Exposure and Corporate Screening

In industrial and corporate settings, prolonged exposure to noise levels exceeding 85 decibels (dBA) poses a severe risk to employee health. Employers utilize Pure Tone Audiometry as a primary tool for occupational health surveillance. Regular testing helps detect early signs of noise-induced hearing loss, which typically manifests as a localized dip or “notch” in hearing sensitivity at 4000 Hz. Identifying these changes early allows corporations to implement engineering controls, enforce the use of personal protective equipment (PPE) like earplugs or earmuffs, and adjust work shifts to prevent permanent disability, thereby ensuring compliance with national labor laws and international safety standards.

Sudden or Progressive Hearing Loss

Physicians frequently request a PTA when a patient reports a sudden or gradual decline in their ability to hear. Sudden Sensorineural Hearing Loss (SSNHL) is considered a medical emergency, often requiring prompt corticosteroid therapy. PTA is crucial in these cases to confirm the diagnosis, determine the severity of the loss, and monitor the recovery process. For progressive hearing loss, which is common in elderly populations (presbycusis) or individuals with a family history of hearing impairment, PTA provides a detailed baseline to track the rate of decline and guide the fitting of assistive hearing devices.

Chronic Tinnitus and Ear Fullness

Tinnitus, characterized by a persistent ringing, buzzing, or hissing sound in the ears, is often a secondary symptom of underlying damage to the auditory system. Patients presenting with chronic tinnitus or a sensation of fullness in the ears require a comprehensive PTA. By mapping the patient’s hearing thresholds, the audiologist can determine if the tinnitus is associated with high-frequency hearing loss, cochlear damage, or middle ear pathology. This information is vital for developing targeted management strategies, which may include sound therapy, hearing aids, or medical interventions.

Evaluation of Ototoxic Medication Effects

Certain essential medical treatments involve drugs that are known to be ototoxic, meaning they can cause permanent damage to the sensory cells of the inner ear. Patients undergoing chemotherapy with platinum-based agents (such as cisplatin), receiving long-term intravenous aminoglycoside antibiotics (like gentamicin), or taking high doses of loop diuretics require baseline and serial Pure Tone Audiometry. Regular monitoring allows clinicians to detect early, subclinical high-frequency hearing loss before it affects conversational speech frequencies, enabling the medical team to adjust drug dosages or alternative therapies when clinically feasible.

Pre-Employment Medical Evaluations

Many corporate entities, particularly in sectors like aviation, maritime, law enforcement, public transport, and defense, require candidate hearing assessments as part of pre-employment medical clearances. These professions demand high levels of situational awareness and clear communication for safety. PTA ensures that prospective employees possess the necessary hearing acuity to perform their duties safely and effectively. It also establishes a legal baseline of the employee’s hearing status prior to any occupational exposure within the company.

What Does a Pure Tone Audiometry (PTA) Detect?

Pure Tone Audiometry is a highly sensitive diagnostic test capable of detecting a wide array of physiological and pathological conditions affecting the auditory pathway. By analyzing the resulting audiogram, clinical specialists can identify:

• Normal Hearing Sensitivity: Thresholds between -10 dB HL and 20 dB HL across all tested frequencies, indicating a healthy, intact auditory system.
• Mild Hearing Loss: Thresholds between 21 dB HL and 40 dB HL, where the patient may struggle to hear soft speech in noisy environments.
• Moderate Hearing Loss: Thresholds between 41 dB HL and 55 dB HL, causing difficulty understanding normal conversational speech without amplification.
• Moderately Severe Hearing Loss: Thresholds between 56 dB HL and 70 dB HL, significantly impacting daily communication and speech perception.
• Severe Hearing Loss: Thresholds between 71 dB HL and 90 dB HL, where the patient cannot hear normal speech and relies heavily on visual cues or powerful hearing aids.
• Profound Hearing Loss: Thresholds exceeding 90 dB HL, indicating an inability to hear even very loud sounds, often requiring cochlear implant evaluation.
• Conductive Hearing Loss: Characterized by normal bone conduction thresholds but impaired air conduction thresholds, resulting in an air-bone gap of 15 dB or more, indicating pathology in the outer or middle ear.
• Sensorineural Hearing Loss: Characterized by equally impaired air and bone conduction thresholds with no significant air-bone gap, indicating inner ear or auditory nerve damage.
• Mixed Hearing Loss: A combination of both conductive and sensorineural components, showing impairment in both pathways with an air-bone gap present.
• Occupational Noise-Induced Hearing Loss (NIHL): Classically demonstrated by a bilateral, symmetrical sensory loss with a distinct “notch” or drop in sensitivity at 4000 Hz, recovering slightly at 8000 Hz.
• Presbycusis: Age-related hearing loss, typically presenting as a bilateral, symmetrical, gradually sloping high-frequency sensorineural hearing loss.
• Otosclerosis: A metabolic bone disease of the middle ear, often showing a conductive loss with a characteristic drop in bone conduction thresholds at 2000 Hz, known as Carhart’s Notch.
• Meniere’s Disease: A disorder of the inner ear characterized by fluctuating, low-frequency sensorineural hearing loss, often accompanied by vertigo and tinnitus.
• Acoustic Neuroma (Vestibular Schwannoma): A benign tumor on the vestibular nerve, suggested by an asymmetrical high-frequency sensorineural hearing loss between the two ears.
• Tympanic Membrane Perforation: Leads to a mild-to-moderate conductive hearing loss, with the degree of loss often correlating with the size and location of the tear.
• Otitis Media with Effusion: Fluid accumulation in the middle ear space, resulting in a flat or low-frequency conductive hearing loss due to restricted tympanic membrane mobility.
• Eustachian Tube Dysfunction: Causes mild, fluctuating conductive hearing loss and feelings of ear pressure due to improper middle ear ventilation.
• Ossicular Chain Discontinuity: Disruption of the tiny middle ear bones (malleus, incus, stapes) due to trauma or infection, causing a significant conductive hearing loss of up to 50-60 dB.
• Barotrauma: Damage to the middle or inner ear caused by rapid pressure changes (e.g., scuba diving or flying), presenting as sudden conductive or sensorineural loss.
• Ototoxicity: Early-stage damage from toxic substances, appearing as a bilateral drop in high-frequency thresholds (above 8000 Hz) before progressing to lower frequencies.
• Congenital Hearing Impairments: Genetic or prenatal factors causing stable or progressive sensorineural deficits detectable from early childhood.
• Functional or Non-Organic Hearing Loss: Discrepancies in test re-test reliability or inconsistencies between subjective PTA thresholds and objective physiological tests, sometimes observed in corporate compensation claims.

Turnaround Time and Report Access at Chughtai Lab

Chughtai Lab is widely recognized across Pakistan for its commitment to efficiency, accuracy, and patient convenience. For Pure Tone Audiometry, which is a real-time behavioral diagnostic test, the preliminary findings are recorded immediately on an audiogram chart by the performing audiologist. The finalized, professionally verified report is typically compiled and made available within a few hours of the test completion. This rapid turnaround is highly beneficial for corporate clients who require prompt medical clearances for their workforce.

Patients and corporate administrators can access the diagnostic reports seamlessly through Chughtai Lab’s advanced digital infrastructure. Once the report is verified, an automated SMS notification containing a direct download link is sent to the patient’s registered mobile number. Reports can also be accessed online via the official Chughtai Lab website portal or through the user-friendly Chughtai Lab Mobile App, available on both iOS and Android platforms. For corporate clients, customized bulk reporting and secure data portals are available to streamline occupational health record-keeping. Physical copies of the report can also be collected from any Chughtai Lab collection center across the country.

Pure Tone Audiometry (PTA) Findings Overview

The following table provides an overview of the typical parameters evaluated during a Pure Tone Audiometry examination, comparing normal physiological responses with potential pathological findings:

Structure / Parameter Evaluated	Normal Findings	Possible Abnormal Findings
Air Conduction Thresholds (Right & Left Ear)	Thresholds between -10 and 20 dB HL across all frequencies (250 Hz to 8000 Hz).	Thresholds greater than 20 dB HL, indicating mild, moderate, severe, or profound hearing impairment.
Bone Conduction Thresholds (Right & Left Ear)	Thresholds between -10 and 20 dB HL, matching air conduction thresholds.	Thresholds greater than 20 dB HL, indicating sensory or neural damage within the cochlea or auditory nerve.
Air-Bone Gap (ABG)	Difference of less than 15 dB between air and bone conduction thresholds.	An ABG of 15 dB or greater, indicating a conductive hearing loss caused by outer or middle ear pathology.
Symmetry Between Ears	Symmetrical hearing thresholds in both ears (difference of less than 15 dB at all frequencies).	Asymmetrical hearing thresholds, raising suspicion for unilateral pathologies such as acoustic neuroma or localized trauma.
High-Frequency Configuration (4000 Hz – 8000 Hz)	Flat, stable thresholds within the normal range.	A sharp drop or “notch” at 4000 Hz (typical of noise-induced damage) or a sloping decline (typical of presbycusis or ototoxicity).
Low-Frequency Configuration (250 Hz – 500 Hz)	Flat, stable thresholds within the normal range.	Rising or low-frequency sensorineural loss (often associated with early-stage Meniere’s disease) or low-frequency conductive loss.
Response Consistency	Highly consistent responses (within +/- 5 dB) upon repeated presentation of identical tones.	Inconsistent responses, suggesting patient fatigue, cognitive difficulty, misunderstanding of instructions, or non-organic hearing loss.

Note: Diagnostic findings should always be interpreted by a qualified healthcare professional together with the patient’s symptoms, medical history, physical examination, laboratory investigations, previous imaging studies, and other relevant clinical information. Additional investigations or specialist consultation may be recommended depending on the findings.

Why Choose Chughtai Lab for Pure Tone Audiometry (PTA)?

• Experienced Healthcare Professionals: Chughtai Lab employs highly qualified, certified audiologists and experienced technicians dedicated to performing precise audiological assessments.
• Patient-Focused Care: Every patient is guided through the testing process with care, patience, and clear instructions, ensuring a comfortable and stress-free diagnostic experience.
• Quality Diagnostic Services: The lab adheres to stringent international quality control standards, ensuring that all diagnostic equipment is regularly calibrated to maintain absolute accuracy.
• Professional Reporting: Audiograms are interpreted and verified by qualified specialists, providing clear, detailed, and clinically actionable reports for physicians and corporate clients.
• Modern Diagnostic Approach: Chughtai Lab utilizes advanced, state-of-the-art audiometers and sound-treated audiometric booths that meet ANSI and ISO standards for ambient noise levels.
• Comfortable Environment: The diagnostic centers are designed to offer a clean, professional, and welcoming environment, ensuring patient comfort throughout the visit.
• Convenient Location: With an extensive network of diagnostic centers and collection points across Lahore, Karachi, Islamabad, and other major cities in Pakistan, accessing services is highly convenient.
• Commitment to Accurate Diagnosis: Chughtai Lab’s dedication to clinical excellence and advanced technology ensures highly reliable results, making it the trusted choice for individual patients and major corporate organizations nationwide.